Lesson Notes By Weeks and Term v4 - SHS 1
AGRICULTURAL MACHINERIES
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AGRICULTURAL MACHINERIES
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Subject: Agricultural Science
Class: SHS 1
Term: 1st Term
Week: 9
Grade code: 1.1.3.LI.2
Strand code: 1
Sub-strand code: 3
Content standard code: 1.1.3.CS.2
Indicator code: 1.1.3.LI.2
Theme: NEW DAWN IN AGRICULTURE
Subtheme: AGRICULTURAL MACHINERIES
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This lesson introduces you to the exciting world of agricultural machinery. For generations, farming in Ghana has relied heavily on manual tools like the cutlass and hoe. While effective for small-scale farming, these tools involve a lot of physical effort (drudgery) and limit the amount of land a farmer can cultivate. As Ghana aims for food self-sufficiency and to make agriculture a profitable business, we must embrace modern technology. Agricultural machinery helps us to farm larger areas, work faster, reduce labour costs, and increase crop yields.
A. Defining Agricultural Machinery Agricultural Machinery refers to the machines and mechanical devices used in farming to reduce human and animal labour and improve efficiency. These range from simple, hand-held power tools to large, complex machines like tractors and combine harvesters.
It's important to distinguish between: Tools: Simple implements held in the hand, powered by human muscle (e.g., cutlass, hoe, shovel). Implements: Devices that are pulled or powered by a source like an animal or a tractor. They do not have their own engine (e.g., a plough, a harrow). Machines: Complex devices with their own power source, usually an engine (e.g., a tractor, a combine harvester, a power tiller).
The Tractor is the most important machine on a modern farm. It is the "prime mover" that provides the power to pull implements and power other machines. Key parts of a tractor you should know are: Engine: Provides the power. Wheels: For movement and traction. Three-Point Hitch: A system at the back for attaching and lifting implements like ploughs. Power Take-Off (PTO) Shaft: A spinning shaft at the back that transfers engine power to implements that need it (like a slasher or a water pump). B. Classification of Agricultural Machinery by Function
We can group farm machinery based on the job it does on the farm. The main stages are: Land Preparation, Planting, Crop Care, and Harvesting. Land Preparation (Tillage) Machinery Tillage is the process of preparing the soil for planting. It involves loosening the soil, controlling weeds, and mixing in organic matter. Primary Tillage Machinery: Used for the first, deep ploughing of the soil. This breaks up hard, compacted land. Mouldboard Plough: This is the classic plough. It has a curved blade (the mouldboard) that cuts into the soil and completely turns it over. This is very good for burying weeds and crop residue. It is best used in soft, stone-free soils common in the forest zones of Ghana. Disc Plough: This plough uses a set of large, heavy, rotating steel discs. It is excellent for hard, dry, or sticky soils and can roll over stones and roots. This makes it very suitable for the savanna zones of Ghana (e.g., Northern, Savannah, Upper East/West Regions). Secondary Tillage Machinery: Used after primary tillage to break up large soil clods, level the seedbed, and create a fine texture suitable for planting. Harrows: These are used to smooth the soil surface. *Disc Harrow:* Similar to a disc plough but with smaller discs, used for shallower work. *Spike-tooth Harrow:* A frame with many iron spikes that are dragged over the soil to break up clods and smooth the surface. Rotavator (or Rotary Tiller): A machine with rotating blades that actively churn and mix the soil. It can sometimes perform both primary and secondary tillage in one pass on lighter soils. Planting Machinery These machines are designed to place seeds or seedlings into the soil with precision. Seed Drill: Sows seeds in neat rows and at a specific depth. It covers the seeds with soil after dropping them. Using a seed drill for maize or rice ensures a uniform plant population, which leads to higher yields compared to broadcasting (scattering seeds by hand). Planter: Similar to a seed drill but designed for larger seeds like maize, beans, and groundnuts. It plants them at specific distances from each other within the row. Transplanter: A machine used to plant young plants (seedlings) that were grown in a nursery, such as rice or tomato seedlings. Crop Care and Management Machinery These machines are used after planting but before harvesting to protect and nourish the crop. Sprayers: Used to apply liquids like pesticides, herbicides, and liquid fertilizers. *Knapsack Sprayer:* Carried on the back, operated by a hand pump. Very common among small-scale cocoa and vegetable farmers in Ghana. *Boom Sprayer:* A large sprayer with a long arm (boom) fitted with many nozzles. It is attached to a tractor and can cover a large area quickly. Used on large commercial farms like pineapple plantations. Fertilizer Spreader/Broadcaster: Distributes granular fertilizer evenly over a field. Harvesting Machinery These machines are used to gather mature crops from the field. Combine Harvester: A remarkable, multi-functional machine. It is called a "combine" because it *combines* three separate harvesting operations: Reaping: Cutting the standing crop (e.g., rice, maize, sorghum). Threshing: Separating the grain from the rest of the plant (the stalk/straw). Winnowing: Cleaning the grain by blowing away the light chaff and dirt. This machine dramatically reduces labour needs and post-harvest losses for grain farmers. It is becoming more common on large rice farms in areas like the Fumbisi and Afife irrigation projects. Reaper/Binder: Cuts the crop and ties it into bundles (sheaves). Root Crop Harvester: Machines designed to dig up root and tuber crops like potatoes, yams, or cassava.